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SN 2022prv: photometry and spectroscopy before brightness maximumстатья
- Авторы: Barsukova E.A., Vinokurov A.S., Valeev A.F., Goranskij V.P.
- Журнал: The Astronomer’s Telegram
- Номер: 15547
- Год издания: 2022
- Первая страница: 1
- Последняя страница: 1
- Аннотация: Optical transient AT2022prv (PS22gjh) in the galaxy IC 1132 was observed at Lick Observatory on 2022 July 28 and classified as SN II or LBV outburst having absolute magnitude of -15.2 (ATEL #15530). We performed additional observations of this transient on August 1 and 3 using Russian 6-m telescope and SCORPIO multi-mode focal reducer (Afanasiev V.L. & Moiseev A.V., 2005, Astron. Letters, V.31, p.194). The comparison star for BV(RI)c photometry was the SDSS standard in the field of IC 1132 with the position ra=235.0172, dec=20.6939. Its SDSS magnitudes were transformed into the Vega BV(RI)c magnitudes: B=16.37, V=15.54, Rc=15.08, Ic=14.67. UT date of observations, V magnitudes, B-V, V-R and R-I color indices of AT2022prv were as follows: UT V B-V V-R R-I: 2022 Aug 1.88 17.06 -0.03 +0.11 +0.01; 2022 Aug 3.86 16.77 -0.17 +0.15 -0.03. Our observations show continuous increase of the star brightness to the level 2 magnitudes above the Lick data. Probably the explosion did not reach its maximum on Aug 3. On this date, the transient reached absolute V magnitude Mv= -17.58 ± 0.15 mag. Its classification as SN II is now undeniable. We have taken the blue spectrum of AT2022prv on 2022 Aug 1.90 UT (spectral range 3760-5355 Å, spectral resolution of 5.7 Å), another blue spectrum on 2022 Aug 3.89 UT (3670-5360 Å, 5.7 Å) and the red spectrum on Aug 3.88 UT (5629-7338 Å, 5.0 Å). Spectra show hot blue continuum with broad emission features. The strongest double-peak feature is He II 4686 Å line merged with Bowen C III + N III blend. Its equivalent width EW = -40 Å, and FWZI is of about 11000 km/s. All the lines consist of a narrow central peak and very wide intensive wings. FWHM of central peak of hydrogen lines was about 400 km/s on Aug 1 but expanded to 900 km/s on Aug 3. While FWZI of hydrogen lines are between 8500 and 10200 km/s. This supernova is very similar to the supernova 1998S in NGC 3877 (Q.-Z. Liu, J.-Y. Hu, H.-R. Hang et al., 2000, Astron. Astrophys. Suppl. Ser. 144, p.219), because it also has Wolf-Rayet star features in the pre-maximum spectrum, and it has narrow emission components superposed on a broad component same as the rare IIn type class of supernovae. The structure of the emission lines suggests the explosion of the SN in hydrogen-rich environment.
- Добавил в систему: Горанский Виталий Петрович